Contemporary society needs teachers who are motivated and equipped to function as social change-agents and policy entrepreneurs for sustainability, including education for sustainable consumption, which is targeted as one of the 2030 SD goals to transform consumption patterns and cultural attitudes and norms regarding consumerism. This case study explored: how an environmental and sustainability education center in the largest waste treatment facility in Israel manifests its role as a social change-agent and street-level-policy-entrepreneur (SLPE) for sustainability in its teacher professional development (TPD) programs and their impact on developing these attributes in K-9 teachers. Semi-structured in-depth interviews and focus groups were conducted with the educational center's senior staff and with 19 K-9 teachers who participated in PD programs. Policy documents and PD curricula supplemented information on the center's educational vision and how it translates into content and pedagogies. Findings indicate that the center's educators function as SLPEs. The TPD impact on teachers is partial but notable, with greater effect in cultivating change-agency competencies among kindergarten and elementary-school teachers compared to middle school teachers. Findings highlight the necessity of PD programs to address the different needs and challenges confronting teachers of different age-level students.